Well-established power distribution systems exist throughout most of the United States, and other countries, which provide power to customers via power lines. With some modification, the infrastructure of the existing power distribution systems can be used to provide data communication in addition to power delivery, thereby forming a power line communication system (PLCS). In other words, existing power lines that already have been run to many homes and offices, can be used to carry data signals to and from the homes and offices. These data signals are communicated on and off the power lines at various points in the power line communication system, such as, for example, near homes, offices, Internet service providers, and the like.
While the concept may sound simple, there are many challenges to overcome in order to use power lines for data communication. Overhead power lines are not designed to provide high speed data communications and are very susceptible to interference. Additionally, federal regulations limit the amount of radiated energy of a power line communication system, which therefore limits the strength of the data signal that can be injected onto power lines (especially overhead power lines). Consequently, due to the attenuation of the communications signals caused by the power lines, communications signals typically will travel only a relatively short distance on power lines. In addition, the distance may vary from location to location.
Power system transformers are one obstacle to using power distribution lines for data communication. Transformers act as a low-pass filter, passing the low frequency (e.g., the 50 or 60 Hz) power signals and impeding the high frequency signals (e.g., frequencies typically used for broadband data communication). As such, power line communication systems face the challenge of communicating the data signals around, or through, the distribution transformers.
In addition, power lines are susceptible to ingress noise, which may vary from location to location. As a result, layout and network planning of a power line communications system may be difficult due to the unpredictability of the power line communications channels. In addition, one of the more expensive aspects of the power line communications systems is installing backhaul media, such as fiber optic cables or wireless networks, to provide a backhaul link between a portion of the PLCS and a conventional network connection (e.g., a point of presence or POP). Thus, there is a need for a power line communications system and method that can reduce the need for backhaul media and extend the communication range of network elements, while reliably and economically servicing customers. These and other advantages may be provided by various embodiments of the present invention.